Circulation.



PATENTBD MAY 26, 190s.

F. P. DEWEY.'

GIRGULATION. APPLICATION. FIL'ED PEB. 26, 1906.

@wwwmw ffw f v tion of a part of a modification.

" My invention consists in causi FREDRIC'TERKINS DEWEY, OF WASHINGTON, DISTRICT COLUMBIA.

CIRCULATION. f Y

i Specification Lgttersfratent. v :Patented May 26,1908.

Application mea February afi-,11996. seriaiNo. 303,082.

To all whom it may concern: 4 Be it known that I, FREDERIC PERKINS DEWEY, a citizen ofthe United States, residing at Washington, in the District of Columbia, have invented certain new and useful Improvements in Circulation, of which ther following is a'specification.

My invention relates to an improvement in circulation, whereby a current of reactive gas causes a steady circulation of liquid, and primarily to the treatment of copper ores,

ut it is also applicable for producing chemical changes in general by the action of gases. on liquids, and especially liquids holding lfinely divided material in suspension to be acted upon by the liquid.

ng the circuf lation of the liquid by the particular manner of introducing the reactive gas'into the liq.- uid in addition to bringing the gas and liquid into intimate contact under conditions most favorable for accomplishing the desired chemical changes.

In the accompanying drawings Figure 1 represents a vertical section of my improved apparatus and Fig. 2 is asimilar sec- My apparatus consists of a containing vessel or tank a, whichfmay be constructed of any suitable material according to the char acter' of the liquid o erated upon andthe chemical re-actions W 'ch take place,` such as Wood, stone, metal, cement, earthen-ware, etc. This tank may be o en or provided with a cover as desired. ithin thetank is a tube b, open at both ends and suitablysupported so as to be separated by an 'annular space from the tank c. This tube may be supported byinclined braces c, as shown in Fig. 1, or by braces from the bottom of the tank, or it may behung by straps from the cover. It may be made ofthe same/mates" rial as the tank a, but. is not necessarily so made.

. Within the tube or cylinder t is-a gas inlet pipe d, which communicates by two or' more ranches e with a horizontal ring ,f provided with 'numerous the bottom;

I do not restrict myself, however, to the form shown in Fig. 1, as the lower end of this pipe d may be a simple closed' pipe with small holes drilled in the end and even ypart wayup the sides. It may also end in a suitable erforated coil, or it may be branched and t e branches perforated.

perforations g, located nearV Vthe well known Krting steam blower.

-In Fig. 1, I have shown this pipe d as coming in through the. top of the tank, but, obviously, it may come in through the bottoni or through the sides, the essential point being .that Ithis tube shall be perforated so as to deliver numerous small bubbles of gas into the. tube b at various points, when the apparatus is in operation.

A suitable discharge opening 7L is rovided near the lower part of the tank,.whic imay be clgsed by a door i. The ore orother mate- /Iial to be treated is fed in at the top of the tank, preferably outside of the tube b.. `When the tankl a is covered, the cover may be provided with suitable openings for introducing the charge and for the escape of the waste gases., If desired, said gases may be Caused to escape through a weighted valve .-in order to maintain a certain pressure diiring the operation of the gases. The relactive gases are caused to pass through the pi e d by any suitable 'blowing apparatus, suc as an air pump or fan, and in case. the material operated upon is of such a character that the re-actions are facilitated by heat, the gases maybe forced in by a steam blower, such as .some cases, if the tank a is provided with a tight cover, the gases may be caused to pass through the pipe d by a suction apparatus applied near the top of the tank c1.. d

The operation of my device as shown in Fig. 1, is as follows: The liquid to be operated upon, or the liquid containing comminuted material in suspension, is introduced into the tank a to the proper depth, preferably just below'the top of the tube b. The tube b being open at the bottom is simultaneously filled. Then the re-ac'tive gases or mixture Vof gases designed to act chemically oir/ the liquid^ o rv i1pon theselidsrr'speidl'iin the "liquid, is forced into the liquid through the perforations in the pipe d and bubbles up through the tube b, carrying the liquid. and solid matter suspended therein with it, thereby causing an upward How through the tube b, andconsequently, .a downward flow around said tube, thus.thoi'oughly mixing the gases, liquid, and solid, and facilitating the chemical re-actions, on account of the vigorous stirring of the whole mass, and because each bubble presents to the liquid a large surface -of gas, which is thus rapidly absorbed, and this also hastens the chemical re-act'ioiis desired. AThe circulation is caused by the fact that the numerous bubbles of gas in the tube InV -' gravity than the liquidoutside of the tube b,l

; render the liquid therein of a 'less specific whereupon the liquid in the tube b rises and -flowsover the edge thereof, while the. liquid outside of the tube b falls and enters said tube at the bottom. As soon as the liquid reaches the top of the tube b, it of course loses its residual gas and becomes heavier, which alsoaids' in the downward fiow of the liquid around the outside of the tube Z1.

In the modification shown in F ig. 2, the lower part of the tube b is connected with the tank a by a ltering material In this case the tank a is provided with'an opening c just above the filtering material y' for the discharge of the solid material, which opening is closed by a door l, m represents a pipe for the discharge of the liquid, which is provided with va valve n. In this modification the solid does not circulate to any appreciable extent around the tube b, as the ilter y' prev vents this.

In some cases the primary chemical action upon the liquid itself or the salts held in solution, may be allthat is desired, but in many cases, secondary chemical re-actions may be obtained on the solid material held in suspension in a finely divided condition within the liquid, which solid circulates with the liquid, and this is the chiefiapplication of my invention. Byit the cost `of carrying on various chemical and metallurgical processes liquid within theJtube b and to employ the chemical substances thus produced in acting on solid material packed around the 'tube b.

In this case, the apparatus shown in Fig. 2

is used. s

The treatment of the lowgrade oxidized silicious copper ores, which my invention'is especially designed for, varies according to the character of the ore. If thev ore carries the copper finely disseminated through 4a comparatively close gangue, it is crushed fine, so that it will pass through a sieve from sixty to one hundred mesh or more and introduced into the apparatus at any convenient point with enough water to make an easily flowing pulp. Then a mixture of sulfurous acid, SO2, and air is passed into theap aratus through the pipe d, preferably by a Ilprting injector. Perhaps the simplest way ofconsidering the chemical re-action isfcopper may be recovered by the e to consider that fthe sulfuiousY acid first attacks the copper, forming copper sulfite, and this is immediately oxidized by the air to copper sulfate,'bu t other re-ac'tions are quite possible, and the re-actions which really take place are undoubtedly much more complex. However, theqfinal result of the joint action of the air and sulfurous acid is the formation of copper sulfate which goes into .l solution in the water.

The sulfurousac'id required may be ob-l y tained in any suitable way, as by the combustion of sulfur in an ordinary sulfur burner,

or by the roasting of pyrites, or similar sul-- furet ores in vany of theordinary roasters. In some cases, the gases obtained from the roasting of auriferous sulfids in preparing them for further treatment may be utilized to advantage. r

When the copper in the ore has practically all gone into solution, the charge is withdrawn from the apparatus. The residuejis then separated from the solution' by` any ordinary means, as by filtering and washing.

The residue may then be treated for the recovery of any valuable metal it may still con:

tain', or otherwise utilized,- or i't.may,bel`

thrown'away.

The copper sulfate solution may be treated in various ways to utilize the copper it contains.

Crystalized bluestone may be re covered from it inpthe ordinary` way. It

may be run over'scrap iron to precipitate the copper as ,cement copper, which is then melted and refined to ingotl copper. The

ectric current in the ordinary way,l or the solution may be util-ized in various other ways. The last washings of the ore residue, which are lowl in copper,v are preferably returned to the Alos` dissolving apparatus to be used in the treatment -of a fresh lot ofore. l/Vhen, however, the ore is-open and porous,

or the copper is coarsely disseminated through the'gangue, a high extraction can oftenbe secured by employing the modified apparatus having a "filter, as shownv in Fig. 2. In this case, the coarsely crushedbre is fed into the space betweentheparts (1f-andb` upon the filter with the addition of the proper amount of water, or preferablywashings from a prev ,ious charge. 'Amixtureolf sulfurous acid and airis then forcedin throu htlie'pipe d,-when the-sulfurous acid isoxid'lzedf-bythe oxygen of the air, particularlylin lthe/presence of oxygen transferring; agents'fV such as sulfate of copper, fomiingi "'s uifuric acid, `which flows up through-thetiibef'b and down out-- side'oi'it upon the pre. Here the acidattacks the copper, formingstilfate `of copper as before, and.`the' .solutinftravels\on until it comesinto the'bottpm of thetube bagain, where it is chargedavfth r,more acid; this action continuing over :and lover, The circulation is continued-until practidlly allthe i ore.

copper is dissolved out of the ore, when the solution is withdrawn and treatedf'or the copper it contains and the residue washedand disposed of.`

Low grade-sulfuret or'esof copper'may be roasted and then treated by my invention,

and the gases obtained 'in the roasting may be utilized as sourceof the sulfurous acid in dissolving the copper out of the-roasted Furthermore, copper matte may b'e roasted and treated for the production of bluestone in my apparatus, and the gases developedin the preparation .of the matte will supply the sulfurous acid required.

While my invention is especially designed toi` treating copper ores, it is evident that it may` be used for various other purposes, such as in the cyanid process of extracting precious metals, in the boiling of wood to convert it into paper pulp, and for the preparation of the solution of alkaline suliite used in pulp boiling, Furthermore, water may be aerated or,.puriiied, oils bleached, and solutions freed 'from iron by blowing air through them, and the air may be ozonized previous to its use in desired purpose.`

In the drawing I have shown -tlie gas delivery ipe within the inner tube. It is my apparatus for any obvious, owever, that it could be located in the space between the outer andrthe inner tube, in whiclrcase the direction of the circulation of liquid would be reversed,'f'or" am'ple: a perforated circular pipe could be used in the annular space between the tank a and the tube b.

A Having thus describedA my invention, what I claim as new and desire to secure by Letters Patent, is:

chemical re-actions causingu the circulation of aliquidfwliich consists in maintain- ;ingntw columns of liquid in direct contact at their lower ends, introducing numerous bubbles of re-active gas at various points within onecolurnn of tlieliquid, permitting.

the gas to re-act freely with the liquid, allowing the residual gas to escape Jfrom the liquid, and causing the liquid to move in a circula'- try, path ,by this alternate addition and escape of gas, substantially as describedf 2. The processoi treating comminuted .material suspended in a liquid h\`y'hich con- 1.- The double process of sists in introducing numerous). bubbles of reactive gas at various pointswithin'a portion of the liquid, ermittjng thelgasl tore-act with the liquid, a lowing the residual as to escape from ythe liquid and causing the 'quid and the coinminuted solid suspended therein to move in a circulatory .path by this alter- Anate addition and `escape of gas, substan-v tially as described. g Y Y Y. 3. lThe process of treating ores, which consists in crushing the ore, mixing the coinminuted ore with a liquid and introducing numerous bubbles of re-active gasat various points within a portion'of the liquid, perl niitting the gas to rel-act with the liquid, allowing the residual gas to escape from the liquid, and causingthe liquid and thecomminuted ore suspended therein to move in a circulatory path by this alternatel addition and escape of gas,\subs,tantially as described. y

4. The process of treating copper ores, which consists in crushing the ore, mixing the coinininuted ore .with a liquid, introducing numerous bubbles of a mixture of air and sulfurous acid at various points within apoition of the liquid,permitting the gas to re-act with the liquid, allowing the residual gas to escape from theI liquid, and causing the liquidand the coinminutedore sus'ended therein to move in a circulatory path y this alternate addition and escape of'gas, substantially asdescribed. 5. The process 4of treating copper ores,

which consists in crushing the ore, mixing the' comininuted ore with a liquid, introducingv numerous bubbles of a mixture oi" air and suliurous acid at Various points within a portion of the liquid, permitting thegas to react with the liquid, allowing the residual gas 

